Magnetic sweepers are well known and have been in use for many years to clear an area of ferro-metallic materials as for example nails and the like from a construction site. Such sweepers have achieved wide spread use and there has been a continuing effort to improve on apparatus that use magnetic attraction for collecting ferro-metallic debris.
For example, a U.S. Patent of Vernon et al. No. 7,331,470 discloses a magnetic raking device that agitates a ground surface and uses magnetic attraction for collecting ferro-metallic debris such as nails and screws, at construction jobsites and other locations. The apparatus includes a release mechanism that temporarily eliminates magnetic attraction of the debris to the rake, thus allowing collected debris to drop from the rake, such as into a trash or recycling container. One type of release mechanism physically removes one or more magnets from the rake body to eliminate magnetic attraction to the rake body. Another type of release mechanism uses electromagnets in the rake body that attract ferro-metallic debris when current is allowed to run through the electromagnets, and that allows the debris to drop from the rake when the current is interrupted. The magnetic rake may be used in an inverted position to attract ferro-metallic debris without agitating soil, and may be used in a non-magnetic state as a conventional rake.
A more recent approach to a magnetic sweeper is disclosed in a U.S. Patent Application Publication No. 2008/0078698 A1 of Lin et al. As disclosed therein a magnetic sweeper is configured to collect magnetic metal debris such as nails, screws, sheet metal fragments, staples, rivets and the like from a surface, and to permit easy removal of the collected debris from the sweeper. The sweeper comprises a non-metallic body, a permanent magnet disposed within the body, a non-metallic cover hingeably mounted to the underside of the body and an integrated latch configured to removably secure the cover to the body. The sweeper is configured to removably engage a handle for controlling the sweeper, and in another embodiment, an extendable telescoping extender may be connected between a coupler and the handle to permit the sweeper to be used in a wide variety of locations. Preferably, the sweeper body is configured to swivel upon application of torque to the handle. In use, the sweeper is passed over metallic debris using the handle to guide the body. As the body passes over such debris, the magnet attracts the debris and holds it against the outer surface of the cover. When debris collection is complete, the cover is unlatched from the body and swung outwardly from the body, thereby displacing the collected debris to a location outside of the magnetic field of the magnet and permitting the debris to fall away from the cover.
Notwithstanding the above, it is presently believed that there is a need and a commercial market for a magnetic sweeper in accordance with the present invention. There should be a need for such sweepers because they are relatively easy to use, include a solar cell for recharging a rechargeable battery, are self contained, relatively compact, easy to use and service and can be manufactured and sold at a competitive cost.
The sweepers in accordance with the present invention is also designed to precede an individual which minimizes the likelihood of the individual being scratched or punctured with metallic debris and at the same time is easy to clean. Further, the sweepers in accordance with the present invention include a collection receptacle or basket which allows an individual to sweep a relatively large area without the need to return to a disposal site or trash bin.